Payette County man diagnosed with West Nile as virus makes its way across the state

Evidence of West Nile virus is mounting in the southern and western parts of the state.

A Payette County man in his 40s has tested positive for West Nile virus (WNV). He is the first human case of West Nile virus reported in Idaho for 2013. He has been diagnosed with a severe form of the infection and is hospitalized.

Payette County was the first in the state to report West Nile-positive mosquitoes during routine surveillance in mid-June; officials there have been aggressively conducting mosquito control activities since. Five other counties in southwest and southern Idaho are also reporting WNV-positive mosquitoes -- Ada, Canyon, Owyhee, Twin Falls, and Washington counties. Infections also have been reported in two unvaccinated horses in Ada and Canyon counties.

“Mosquitoes carrying the West Nile virus are out, and they’re hungry. This first human case serves as a reminder to ‘fight the bite’ of mosquitoes, even if you live in an active mosquito abatement district,” says Dr. Leslie Tengelsen, deputy state epidemiologist. “It is very important that we all prevent mosquito bites and take protective measures, such as wearing repellent and reducing mosquito breeding habitat around our homes.”

West Nile virus is usually contracted from the bite of an infected mosquito; it is not spread from person-to-person through casual contact. Symptoms of infection often include fever, headache, body aches, nausea, and sometimes swollen lymph glands or a skin rash. In some cases the virus can cause severe illness, especially in people older than 50. To reduce the likelihood of infection, people are advised to avoid mosquitoes, particularly between dusk and dawn when mosquitoes are most active. In addition, you should:

Apply DEET or other EPA-approved insect repellent to exposed skin and clothing. Carefully follow instructions on the product label, especially for children.

Cover up exposed skin when outdoors.

Insect-proof your home by repairing or replacing screens.

Reduce standing water on your property. Check and drain toys, trays or pots which may hold water. Change the water in bird baths and static decorative ponds weekly as they may provide a suitable mosquito breeding habitat.

West Nile virus does not usually affect domestic animals, but it can cause severe illness in horses and certain species of birds. Although there is no vaccine available for people, there are several vaccines available for horses. People are advised to vaccinate their horses annually.

Last year, 17 people in Idaho reported West Nile virus infections, with West Nile activity reported in 11 Idaho counties. In 2006, Idaho led the nation in West Nile illnesses with almost 1,000 infections, which contributed to 23 deaths.